1. Field of the Invention
This invention relates to a semiconductor device.
2. Background Art
A conventionally known structure for enhancing breakdown voltage includes a field plate electrode opposed to the frontside of a semiconductor layer across an insulating layer (see, e.g., Japanese Patent No. 3207615). This Japanese patent also discloses using part of the field plate electrode as a gate electrode so as to be opposed to a base region.
For the purpose of further enhancing breakdown voltage and reducing ON resistance, it is theoretically possible to include a field plate electrode and a gate electrode also on the backside of the semiconductor layer so as to be opposed thereto. However, this configuration complicates the extraction structure for the electrodes provided on the backside. Hence it is currently difficult to stably obtain such a configuration, and development of a new device design is expected.